A boiling water reactor (BWR) includes dry tubes that provide a housing within the reactor vessel that positions sensors, such as nuclear flux detectors and protects them from reactor operating pressure, water, and steam. The dry tubes extend from the bottom of the reactor vessel to just below an upper core support grid, and a spring loaded plunger assembly is attached to the upper end of each dry tube to engage the dry tube with an anchor point in the bottom of the upper support grid.
The dry tube may need to be removed and replaced, for example, as sensors in the dry tube stop working. As the dry tube is deployed or installed in the reactor vessel, a welded joint between the spring loaded plunger assembly and the dry tube can become corroded and the plunger assembly can fail to operate properly. As such, the dry tube becomes stuck and difficult to remove and replace. In such instances, attempting to remove the dry tube by operating the plunger assembly can cause the corroded joint to fail and very undesirably cause debris to fall into the reactor.
Therefore, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies. What is needed is an apparatus and method for safely and efficiently removing a dry tube.